Certain lighting assemblies are configured to evenly illuminate a surface in close proximity to the lighting assembly. Such lighting assemblies are used in applications such as theatrical lighting, architectural lighting, display lighting and sign lighting. In the case of theatrical lighting, this type of lighting assembly is referred to as a cyc (abbreviation for cyclorama) light. In architectural lighting, this type of lighting assembly is referred to as a wall wash. Often, multiple lighting assemblies of this type are arrayed to evenly illuminate a wide vertical surface. For example, in the case of theatrical use, a number of these lighting assemblies are located on the stage to evenly illuminate a vertical surface at the back or the side of the stage. It is desirable to locate these lighting assemblies as close as possible to the vertical surface to allow for actors and or other set pieces to be located close to the vertical surface. In the case of architectural lighting, multiple instances of this type of lighting assembly are typically located at the base of a wall or a sign to provide even illumination from top to bottom. In this application, it is also desirable that the lighting assemblies be located as close as possible to the wall or sign.
Another application for this type of lighting assembly is for street lighting. In such an application, an even illumination of the surface of a street is desired. Illuminating an area evenly with a minimum light level reduces the power needed to provide the illumination. Further, by accurately controlling the direction of the light output from the lighting assembly, glare is reduced.
Light-emitting diodes (LEDs) have become bright enough and low enough in cost to make them attractive as a light source for many lighting applications. However, light-emitting diodes typically output light with a substantially hemispherical light ray angle distribution. Challenges therefore exist in efficiently converting the substantially hemispherical light ray-angle distribution of an LED to the asymmetrical light ray angle distribution needed to evenly illuminate a nearby surface.